The session started with a reel of clips from the remaining episodes of the shows inaugural season; including guest spots from Ra's al Ghul and Felicity, a young Det. Lance, scenes from the upcoming trip to the Old West and Jonah Hex, Atom quoting "Terminator" by saying "come with me if you want to live" and much more as Vandal Savage's threat grows deeper -- ending with a tease of the Atom using his powers to seemingly get (much) bigger, rather than smaller.

"We didn't really hold back in that sizzle reel," Guggenheim told the crowd.

Also seen in the sizzle reel: "Firefly" veteran Jewel Staite, who Guggenheim said plays a character with ties to Ray Palmer.

First question was for Guggenheim, asking why he was eager to add "Legends of Tomorrow" to his already-busy slate. (He's co-showrunner on "Arrow," and writer of the "Agents of S.H.I.E.L.D." comic book for Marvel, among other writing projects.) "No one's done it before," Guggenheim said. "No one's done a superhero ensemble on television before." Guggenheim also credited "10-year-old boy me" for being excited about the show.

Guggenheim also answered why Vandal Savage was his favorite DC Comics villain. "It was an issue of 'Flash,' I forget which number, where Vandal is punching the Flash, and kicking the Green Lantern," Guggenheim said. "That was one of the first comic books i owned, it just made an incredible impression."

In terms of putting together the show's ensemble cast, "This was all our first choice," Guggneheim told the crowd. "We just didn't expect them to say yes. That was the surprise."

Guggenheim said it made "total sense" to feature the already-established Atom and White Canary in the series, and that even if "Legends" didn't happen, their stories would have hopefully continued in "Arrow."

TV Guide's Damian Holbrook, the panel's moderator, asked Guggenheim who "reins all this in" in a show with as many characters as "Legends," which also ties-into both "Arrow" and "The Flash." "It's a group effort," Guggenheim answered. "We've got wonderful writers. All of us are comic book nerds. I, at this point, certainly know every episode of 'Arrow' that we've produced. We've got a bunch of people that help us with all the 'Flash' continuity. We work really hard to make it all hang together."

"This has never really been attempted or done," Routh added. "It's daunting. What we haven't done in season one, we'll get in season two."

Lotz and Routh were asked about the shift in tone from "Arrow," with "Legends" having a relatively lighter tone. "That was one of the hardest parts; adjusting to the different tone of the show," Lotz said. "I think because she's gone through so much --she's died, everything has been -- at this point she's like, 'alright," and able to have some levity to it. That's allowed her to adjust. She's got a new lightheartedness that is nice to see for her."

Routh pointed out that he was already been able to do a lot of the lighter moments on "Arrow." "I think he has even a little bit more fun," he continued, "and an opportunity to get a little bit deeper into the drama, especially as we go later into the season."

Renée talked playing Hawkgirl after Hawkman's death, which occurred soon after her character remembered their shared past(s). "I think every twist and turn has helped Kendra grow substantially," she answered. "It's definitely different coming from 'Flash.' I also think her storyline in general was pretty dark to start out with, it wasn't necessarily the happiest one."

If Hawkgirl and Hawkman are destined to be together, why the teases of Ray and Kendra? "Because these two guys are awesome together," Guggenheim said. "Kendra's going to start to remember more of her past lives with Carter. In many ways, Ray is completing with a dead man. We're doing a love triangle where one corner of that triangle is dead. There aren't many shows that can do that."

'"Ray needs to make better choices," Routh joked.

The recent 1950s-set episode of the show, "Night of the Hawk," was the next topic of discussion, with Lotz praising that the installment involved her character's bisexuality, which she pointed out as a very important part of Sara Lance. It was a big episode for Drameh, too.

"We got to see Jax finesse his game a little bit, and show he isn't that hopeless with the ladies," Drameh said. "I really enjoyed that episode -- that was a lot of fun to portray and explore, being a young black guy in that time period. We didn't want to go too, too heavy with it, but it was good to do that."

"It was cool to portray a different Firestorm dynamic," Drameh continued. "Jax is more similar to the comic book Ronnie Raymond in a lot of ways. He's a jock, and him and Stein really don't get along at first. I absolutely love working with Victor."

Drameh was also asked about his character's evolution from his first appearance on "Flash." "I thought that throughout this season, we kind of show Jax grow and mature," Drameh answered. "He starts out really naive. As we progress, he understands there are morally grey areas."

Guggenheim discussed the process of deciding which DC characters end up on the series. "We just have ongoing conversations with DC," Guggenheim said. "It's not really about bartering, it's about communication. 'Hey, this character is locked up in this project -- how about using this character?' That literally just happened, [DC Entertainment Chief Creative Officer] Geoff Johns and I were on the phone last week. It's just a dialogue."

What was the cast's favorite time periods to visit so far? "Wild West," Routh answered. "Just showing up and putting on the western gear, my duster and my hat, was pretty fun." "I feel like I belong in the '70s, so that was a good one for me," Lotz replied. "I really liked the '50s," Renée said, "Because I feel like we got to discuss issues that are relevant to right now."

Lotz teased a development coming up this season: "Sara might sit in a certain captain's chair at some point, and may possibly be flying a time ship. Rip Hunter better watch out, because Captain Canary is coming in."

The panel talked the chemistry between Drameh and Victor Garber, the other half of Firestorm. "Victor's my homey," Drameh said.

Which characters would the cast members want to play other than their own? Renée: "Captain Cold." Drameh: "White Canary. I think I'd rock that outfit." Lotz: "I'd want to be Vandal Savage." Routh: "I might want to be Heat Wave, because he is so funny in his own way."

As an example of this enthusiasm for playing a superhero, Drameh said he had to be told that he didn't have to make sound effects himself while in costume. "We're going to do that in post, it's OK."

Guggenheim promised resolution by the end of the first season -- you'll know if the team is able to stop Vandal Savage; you'll see a resolution of the love triangle between Ray, Kendra and Carter; and you'll get to know more about what the Time Masters are up to. "I don't think there are too many unanswered questions at the end of this season."

In terms of cast shake-ups, "We have a couple of empty chairs on the Waverider," Guggenheim said. "Anything's possible."

First fan question: "How are your characters accepting the motivation of saving the future?" Routh said that while Rip Hunter may have ulterior motives, the rest of the main cast are "all confident we're going to make it in our own way, no matter what he says." Renée said it's a personal fight against Vandal Savage for her. "I've got this one thing I have to do, and I've got to figure out how to do it." "For Sara, it's a little less 'let's save the world" -- we're traveling through time, let's have fun," Lotz answered.

Who would the cast like to see join "Legends?" "I'd love to see more girls," Renée said. "I'd love it if Vixen could be on." Routh mentioned Vixen and John Constantine. "I think it'd be awesome if Killer Frost came back and was on our show," Routh said. "A rogue woman character." "I think we need some Speedy," Lotz said, referring to Willa Holland's "Arrow" character. "And I like Iris West." Guggenheim agreed that "we definitely need more women on the show." In terms of Vixen: "Megalyn [Euchikunwoke] is welcome on any of the shows, any time she wants," Guggenheim assured.

Renée told a fan she's been "journaling" as her character, to keep track of Kendra's many lives.

Last fan question, from a young member of the audience: "Will the time ever travel in the future to see the Justice League?" "It would be pretty cool if we did," Renée answered. "They are going into the future," Guggenheim said. "I think you're going to see the Justice League in the movies before you see them on TV. We sort of consider these guys our Justice League. But there are some cool things coming in the future. Robot Atom!"

Final question came from the moderator: How should people prepare for the "Legends of Tomorrow" season finale? Guggenheim suggested a glass of red wine, because, "There's no reason people shouldn't prepare for the finale the same way I helped write and produce the finale." Lotz said she hopes people have viewing parties -- in costume.